Hitch for trailers having independently pivoted wheels



Dec. 25, 1956 c. H. HOLSCLAW 2,775,468

HITCH FOR TRAILERS HAVING INDEPENDENTLY PIVOTED WHEELS Filed Jan. 25, 1954 2,775,468 nrrcn non TRAILERS HAVING INDEPENDENTLY PIVOTED WHEELS Charles H. Holsclaw, Evansville, Ind.

Application January 25, 1954, Serial No.,405,702

' 4 Claims. 01. 280-457) The present invention relates in general to trailer hitches for connecting wheeled trailers to towing vehicles, and more particularly, to such hitches for trailers having a plurality of wheels individually pivoted thereto about vertical axes. Y

It is the general aim of the invention to provide a trailer hitch for multiple pivot-wheeled trailers which, by a simple and economical organization, not only affords" freedom for relative rocking of the trailer and towing vehicle about a transverse axis and about a fore and aft: 25 axis on unevenground, but also prevents jackknifing of I the trailer and vehicle about a vertical axis.

In a more specific aspect, it is an object of the inven-- tion to provide a trailer hitch which lets the trailer float 30 or road surfaces thereby minimizing stresses on the hitch' relative to the vehicle upon traversing irregular ground connection. At the same time, it is an additional object of the invention to prevent yawing of the trailer by a con-1 nection which positively assures that the trailer will track or follow the towing vehicle and permits steered backing of the two as a unit.

Other objects and advantages will become apparent as the following description proceeds, taken in conjunc-j tion with the accompanying drawings, in which:

Figure 1 is a plan view of a trailer hitch embodying the features of the invention and shown coupling an.

exemplary trailer to a typical towing vehicle;

Fig. 2 is a side elevation of the hitch trailer and vehicle shown in Fig. 1; 1 Fig. 3 is a detail view taken in section substantially along the line 3--3 in Fig. 1;

Fig. 4 is a sectional View taken along theline 44 in Fig. 2 and particularlyillustrating how the hitched trailer may rock about a fore and aft axis relative to the towing vehicle; and

Fig. 5 is a plan view similar to Fig. 1 and illustrating the hitched trailer as it follows the towing vehicle in rounding a corner.

While the invention has been shown and is described in some detail by reference to a particular embodiment thereof, there is no intention that it be thus limited to such detail. On the contrary, it is intended here to cover all alterations, modifications, and equivalents falling within the spirit and scope of the invention as defined by the appended claims.

Referring now to the exemplary embodiment of the invention here shown, a trailer hitch is illustrated as connecting a trailer to a towing vehicle 11.

The trailer 10 and the vehicle 11 may take a variety of forms; examples are here illustrated to make clear the environment and operation of the invention. The trailer 10 inthis instance has a welded steel frame 12 carrying a body 14 and supported for transport by a plurality (here, two) of wheels 16, 17 pivoted to swing freely and independently about spaced vertical axes 16a, 17a. For marginal support of the body 14 and for towing connection, the frame 12 includes an angle beam 18 rounded 2,775,468 Patented Dec. 25, 1956 at the corners and presenting a forward portion on which a connection shank 19 is fastened, as by welding at 20. The towing vehicle 11 is by way of example here partially shown in dashed outline as a conventional automobile having the usual transverse rear bumper 25 with vertical guards 26.

The illustrative trailer hitch includes a central tongue 30, here shown as a tubular member, extending forwardly from the trailer 10. The tongue 30 is adapted to be fas- Q tened to the front of the trailer in this instance by a 7 vertical 'plate 21 welded to the vtongues rearend as at 32. In order that the tongue may be adjustable in height to keep the trailer level when hitched to vehicle bumpers of various elevations, the plate 21 is provided with a series of vertically spaced holes 34 adapted to register in pairs with matching holes 35 in a correspond ing plate 36 secured as by welding at 38 to the shank 19.

A pair'of removable bolts39 fasten the two plates 2 r and 36 in selected relative positions. I

The forward end of the tongue 30 is adapted for swivel connection to the rear of the vehicle 11, as here shown by the provision of a transverse bar 40 having bumper clamps 41 and 42 of conventional construction removably fastening its opposite ends to the bumper 25. The bar 40 carries three transversely spaced ball fittings 44, 45 and 46, the center one 45 receiving a socket member 48 Welded or otherwise secured as at 49 to the tongue 30. Such ball and socket swivel connections are well-known per se, in the art. The socket 48 may be removed at will from the cooperating ball fitting 45'by a release mechanism including a handle 50.

, The hitch as thus far described would work well enough during forward towing on absolutely level ground, providing the trailer were not unsymmetrically loaded.

The best road i surfaces are not perfectly smooth and operation over rough terrain is often necessary with towed trailers.

These ideal conditions are rarely met.

Reverse drive for maneuvering is desirable and often a vital requirement. 7 I a To-permit realization of successful towing and backing 0f the trailer without undue strain on the bumper 25 or the llltCh'COIl'lPOflClJlS, the invention contemplates means for bracing the trailer 10 relative ot the vehicle 11 against yawing movement about a vertical axis, while at the same time permitting relative rocking of the two about a horizontal fore and aft axis on uneven ground. Provision is,

made for a towing connection substantially along the longitudinal center line of the vehicle and for free rotation of lateral braces about such center line as the trailer and vehicle rock-relatively there about.

I n the illustrated form, the means forbracing the: trarler 10 against yawing aboutaverticalaxis relative to gthe trailer includes a bushing or sleeve 51 and a pair of forwardly diverging struts 55, 56. The sleeve 51 is rotatably and slidably disposed on the tongue 30, and the struts 55, 56 are pivoted at their rear ends to opposite sides of the sleeve. Additionally, the struts are adapted to have their forward ends swiveled at spaced locations to the bumper 25.

For a long-wearing smooth fit on the tongue 30, the sleeve 51 may include a bearing 52 inserted therein and may be provided with a lubricating hole 54. The pivotal connection of the struts 55, 56 to the sleeve 51 is accomplished, in this instance by bolts 58, 59 passed through matched openings in the struts 55, 56 and spaced V-shaped ears 60 and 61 secured as by welding at 62 and 63 to the sleeves outer surface. The forward ends of the struts 55, 56 are adapted for swivel connection to the vehicle 11 at points spaced laterally on either side of the center tongue 30. For this purpose, the struts 55, 56 have ball sockets 65 and 66 fastened as by bolts 67 and 68, respectively. The sockets 65, 66 may be similar to socket 48 'a'r'id are 'remavststy re eiv'ed in swiveled relation on the hallfittings '44 and '46, respectively. The spacing of the fittings 44 and 46 may vary considerably according to the width of the vehicle -11 and the size of the trailer t b" ushered. ysn'c'h variations are accommodated by the sea s 55, e, thou'gh ffixed in length, since their diverging angl niaybe increaseti o'ndecreaseH hypivotizjr atft ems; ends, ahd'the sleeve 51 may be moved axially alo'ng -the "tongue '30.

) As the vehicle 11 transportsthe trailer 10, a di'rfeet pull or is "established "through the center tongue 30. traile 1 cannot iskew i'n ahor'izontalplane relative to "the "vehrcle inasmuch as "the struts '55, 3'6 'form rigid b'race' tha'tplaii Theirailer 10, therefore, remains a "inure ately behind the rea offyehic'le -11, c nters byfpivotin'g of its "wheels '16, 17 (Fig 5 N ckldiifingfilative angling about a"vertical axis) can V Qn' the other liahdfshdfildthe'vehicle 11 rise or ative to thetraile'r IQ asin crossing a ditch, the'e'ntire hith'm'ay pivdt about the transverse axis on which the swivel ball joiiitslie *(see "dashed lines, Fig. 2) .And uponbumpy or irregular ground the trailer may rock relative to the vehicle about afor'e and aft axis'defined by tlie ce'hter tongme since "the laterally extending struts 55', 55 may rotate with the "s'leeve5'1 about the center tongue. at V lt will b'e apparent from the foregoing'th'atthe present invention-affords *a trailer hitch which is relativelysimple in construction and "which-can be' readily removed from aj' traile'r o'r *tov'ving vehicle. The single bitch is, therefore-"extremely "versatile "and *can be 'used in towing any dfa number of trailers from different vehicles. Various transverse spacing of the outer swivel'connections on different vehiclesarereadily "accommodated by axiaksli'ding of the sleeve 51 on the tongue 30- -and'fpivoting'of the striits "55,56 to-"diiferent"divergingangles. Still more" important, "however, the hitch struts 55, 56 prevent *jackknifi-ng of I the t'railer and vehicle about "a' vertical 'axis, yetlet the trailer float relative to the vehicle'either about a transverse-axis or about afore and an axison uneven ground.

I claim:

1. A hitch for connecting a trailer supported "on independently pivoted wheels to 'a towing-v'ehicle comprising, in cornbir'lation, a center tongue adapted to 'be rigidly fastened at'one enddo the front ef the trailer adapted at itsio'tlier end 15 for swiv'el attachment to th e *rea'r'o f 'the vehicle, -'a sleeve rotatably t and axially slir'ial'ile "on s'afd center tongue, a pair =of struts eahipivotd at one endto said v"sleeve and adapted -"for swiveled connection atffthe otheriend to' 'Ith'e rea s said vehicle at locations 'lateraily spaced on either side of said-center tongue.

2. A hitch fo'rconnecting a niiiltiplefpivot wheel trailer to a towing vehicle -comprisin'g, -in -'conii5ination,"'a center tongue adapted to be rigidly 3 fastened "to *"tlie? 'frorit 'of the trailer "in forwardly extending relation ihe 1mm,

means at the forward end of said tongue adapted for swivel "connection to the rear of the vehicle, a sleeve rotatably and axially slidable on said tongue, a pair of struts pivoted at one end to said sleeve and adapted at the other end for swiveled connection to the rear of the vehicle at points spaced laterally on either side of said tongue, the lateral spacing-ofsueh points being adjustable upon axially sliding said sleeve along said tongue and rocking :said s'truts relative to said sleeve, saicl struts p'reventing jackknifing of 'said trailer and vehicle, and said sleeve by rotation aboutisaidtongue ;.permitting relative roll of said trailer and vehicle about a fore and aft axis.

3. A hitch for connecting a multiple:pivot wheel trailer to a towing vehicle comprising, incombination, a crossbar adapted to be mounted on the rear of the vehicle and having three ball-connection elements spaced thereon, a center tongue adapted to be rigidly fastened in forwardly extending relation to the front of the trailer, a ball socket fast :on the 5 forward vfilld of said vtongue for aSWiVCl ,connection to the centereo'ne of said :threeball elements, :a sleeverlike element rotatably sand axially :z-slidable on -;said tongue, ;a ;pair of strut-s pivoted at {their t-rearrends .to;opposite sides of said sleeve element and diverging forwardl y I'OWZIdiEhB outer-ones of-zs-aid ball elements, and ballisockets on the forward ends of said struts, for swivel connection'to respectiveiones of saidgouterball elements.

4. IA hitch-for coupling a trailer havingalframet'supported on "a plurality of ground wheels independently pivotedi-about vertical axes to ,an automobile :having a rear bumper, said hite'h comprising, in combination, a crossbar adapted-robe clamped tosaidtbumper-andv-having three;ball.:fittings spaced .therealong,v a tongue adapted to be fastened .in rigid forwardly extending :relation .to saidufra'rne a first ball :socketrigid on the end of said tongue for .removableqswivelconnectiontc the center one of's'aid ball fittings,-a=r.otatab1y andaXiallyslid-able bushing on .saidftongue havingsdiametrically opposed ears a pair. of. struts pivoted at. their rear ends --.to 1 respective-ones of said ears and diverging forwardly, second andthird ballssockets .rigidcon therrespective forward ends o'frsaid struts for removable :swivel connection to .the respective outer ones of said ball; fittings, saidlhall andsocketwconnections tjper'inittingtrielative rocking of the trailer and automobile I about .a: transverse Z axis, rotation of ,said; bushing permitting relativerocking.ofv the trailerandautomobile-about. a "forejand ;aft..axis,, and. said. struts preventing relative jackkriifing 'of said trailer and automobile about a vertical axis.

References Cited in thefile of this [patent UNITED ESTATES EPA-TENTS 2,085,260 Keys 'June 29, 1937 2,464,392 Heavener Mar. -15, 1949 2951-9356 {Schule Aug. 22, 1950 236535032 Ellis Sept. 22, 1953 

